副猪嗜血杆菌潜在毒力因子的综述

副猪嗜血杆菌是引起猪格氏病的病原,多继发感染引起全身性疾病,其高发病率和死亡率给养殖业造成严重损失。作者主要对其潜在毒力因子,包括外膜蛋白ompP5和ompP2、自转运蛋白vtaA、转铁蛋白、6-磷酸葡萄糖酸脱氢酶和毒素等的研究作一综述,并对应用于副猪嗜血杆菌的最新研究方法进行概述,从而形成对其毒力相关研究较全面的认识。

食源性单增李斯特菌14种潜在毒力基因的检测

目的了解新疆生产建设兵团食源性单核细胞增生性增李斯特菌(Listeria monocytogenes,LM)潜在毒力基因分布情况。方法以54株食源性LM DNA为模板,针对14个潜在毒力基因设计特异性引物并利用PCR技术检测潜在毒力基因。结果 54株分离株均携带潜在毒力基因,其中5563分离株携带率最高,为57.14%(8/14),21L662分离株携带率最低,为21.43%(3/14),其余分离株携带率在28.57%(4/14)~50%(7/14)之间。潜在毒力基因检出率不同,其中寡肽转运蛋白、内化素样蛋白、细胞壁表面锚定家族蛋白、单价阳离子/H+逆向转运蛋白、肽聚糖结合蛋白、组氨酸代谢系统、合成致死KAR3样蛋白、精氨酸/鸟氨酸逆向转运蛋白、ABC转运蛋白、Ⅱ型限制酶修饰系统Sau3Al,磷酸葡萄糖转移酶系统基因的检出率分别是98.15%、81.48%、77.78%、64.81%、59.26%、53.70%、51.85%、35.19%、12.96%、9.26%、9.26%,芳香族氨基酸合成因子,EsaC蛋白类似物,差向异构酶/脱水酶家族蛋白和转录调控因子3种潜在毒力基因未检出。结论检测食品源LM分离株14种潜在毒力基因的分布,为研究LM致病性和食品LM的溯源奠定了基础。

HPLC法测定奥美沙坦酯2个氯代基因毒杂质的含量

是为了建立HPLC 法测定奥美沙坦酯原料药中3和氯代基遗传毒杂质的含量。方法 色谱柱为苯基键合硅烷硅胶为填充剂(Kromail Eternity 5-Pheny Hexyl 250×4.6mm,5μm),用磷酸二氢钾溶液(将2.04克的磷酸二氢钾溶于水中,稀释到1000ml,用磷酸将 pH调整到3.2)作为移动相,用乙腈作为移动相 B,用直线梯度法将其从样品中分离出来;该方法的探测波长为215 nm;流量1.0ml/分钟,温度40℃,10μ L进样。结果 结果表明,在0.17μ g/ml—8.5μ g/ml范围之内,3个样品的峰面积与其含量有很好的相关性(r=0.9999),平均加标为98.9%;结果表明,在0.17μ g/ml—8.5μ g/ml范围之内,杂质4与其峰面积之间有很好的相关性(r=0.9999),平均回收率为103.3%;杂质5质量浓度在0.17μg/ml~8.5μg/ml内与峰面积呈良好的线性关系(r=0.9998),平均回收率为97.7%。结论 本方法可用于同时测定奥美沙坦酯原料药中3和氯代基遗传毒杂质的含量,且专属性强,耐用性好。

Natural products against HIV latency

Antiretroviral therapy has achieved great success in suppressing human immunodeficiency virus(HIV)replication and transforming HIV infection from a fatal disease to a manageable chronic disease.However,the latent HIV reservoir persists in the body of HIVinfected individuals and is prone to reactivation.Therefore,the development of new treatment methods aimed at a complete cure for HIV is needed.The leading strategy for HIV eradication is based on eliminating and preventing the reactivation of latent reservoirs through an approach known as“shock and kill.”This strategy involves the use of latency-reversing agents(LRAs)to activate the HIV provirus in latent viral reservoir cells.Many LRAs can be obtained from natural resources,including plants and marine organisms.In this review,we provide an overview of natural products used to eliminate HIV latency.

The miRNAs of Herpes Simplex Virus(HSV)

Herpes simplex virus (HSV) is a group of common human pathogens with two serotypes HSV-1 and HSV-2.The prevalence of HSV is worldwide.It primarily infects humans through epithelial cells,when it introduces a latent infection into the nervous system.During viral latency,only a region known as the latency-associated transcript (LAT) is expressed.The discovery of HSV miRNAs helps to draw a larger picture of the infection and pathogenesis of the virus.This review summarizes miRNAs found in HSV-1 and HSV-2 so far.The functional studies of miRNAs in HSV to date indicate that they play a stage-specific role coordinated with viral proteins to maintain the virus life cycle.

Genetic Variation in Field Populations of Baculoviruses: Mechanisms for Generating Variation and Its Potential Role in Baculovirus Epizootiology

Baculoviridae is a family of insect-specific DNA viruses that have been used as biological control agents for insect pest control. In most cases these baculovirus control agents are natural field isolates that have been selected based on their infectivity and virulence. The advent of molecular tools such as restriction endonucleases, targeted polymerase chain reaction and new DNA sequencing strategies have allowed for efficient detection and characterization of genotypic variants within and among geographic and temporal isolates of baculovirus species. It has become evident that multiple genotypic variants occur even within individual infected larvae. Clonal strains of baculovirus species derived either by in vitro or in vivo approaches have been shown to vary with respect to infectivity and virulence. Many of the cell culture derived plague-purified strains have deletions that interrupt egt expression leading to virus strains that kill infected hosts more quickly. As well, in vitro clones often involve larger genomic deletions with the loss of pif gene function, resulting in strains deficient for oral infectivity. There are an increasing number of baculovirus species for which complete genome sequences are available for more than one strain or field isolate. Results of comparative analysis of these strains indicated that hr regions and bro genes often mark "hot spots" of genetic variability between strains and of potential recombination events. In addition, the degree of nucleotide polymorphisms between and within strains and their role in amino acid substitutions within ORFs and changes in promoter motifs is also beginning to be appreciated. In this short review the potential mechanisms that generate and maintain this genetic diversity within baculovirus populations is discussed, as is the potential role of genetic variation in host-pathogen interactions.

Toxicity of novel anti-hepatitis drug bicyclol: A preclinical study

AIM: To study the toxicity of bicyclol to animals. METHODS: Acute toxicity test was performed in Kunming strain mice that were orally given bicyclol at the doses of 3 and 5 g/kg body weight, respectively. Wistar rats were orally administered bicyclol at a dose of 5 g/kg body weight. Death and clinical symptoms of animals were recorded within 7 d. Sub-acute toxicity test was carried out in rats that were treated with various doses of bicyclol (150, 300, 600 mg/kg) once daily for 14 d. Animal behaviors, blood biochemical markers, blood and urine pictures were examined. Chronic toxicity test was conducted in 80 Wistar rats of both sexes. The animals were orally administered with various doses of bicyclol [150, 300, 600 mg/kg, 100-400 folds corresponding to the proposed therapeutic dose (1.5 mg/(kg·d)) of bicyclol for patients] once daily for 6 mo except for Sunday. The control group was given the same volume of 0.2% sodium carboxyl methylcellulose (Na-CMC). Twenty-one beagle dogs received bicyclol (25, 75, 225 mg/kg, 16.6, 50, 150 folds corresponding to the proposed therapeutic dose of bicyclol for patients) once a day for 6 mo except for Sunday. The body weight, food intake, urine and feces, blood picture, blood biochemical markers, and pathological examination of main organs were determined. Mutagenicity and teratogenicity were determined. Mutagenicity assay included Ames's test, chromosome aberration test in CHL cells and micronucleus test in mice. For the teratogenicity assay, pregnant Wistar rats weighing 200-250 g were treated with 0.2,1.0 g/kg bicyclol once daily from the 7th d of gestation for 10 d. RESULTS: The oral LD50 of bicyclol was over 5 g/kg in mice and rats. No noticeable alterations in subacute and chronic toxicity of rats and dogs were demonstrated. No mutagenicity and teratogenicity of bicyclol were found. CONCLUSION: Bicyclol has no detectable chronic toxicity as well as mutagenicity and teratogenicity in animals.

Negative effects of Phaeocystis globosa on microalgae

The potential allelopathic effects of the microalga,Phaeocystis globosa Scherffel,on three harmful bloom algae,Prorocentrum donghaiense Lu,Chattonella marina(Subrahmanyan) Hara et Chihara and Chattonella ovata Hara et Chihara were studied.The growth of C.marina and C.ovata was markedly reduced when the organisms were co-cultured with P.globosa or cultured in cell-free spent medium.Haemolytic extracts from P.globosa cells in the senescence phase had a similar inhibitory effect on the three harmful bloom algae.However,P.globosa had less influence on the brine shrimp,Artemia salina.These results indicate that P.globosa may have an allelopathic effect on microalgae,which would explain the superior competitive abilities of P.globosa.Because the addition of the haemolytic toxins from P.globosa had similar effects on algae as spent media,these compounds may be involved in the allelopathic action of P.globosa.

呋塞米及其注射液的杂质谱研究

目的:建立HPLC法研究呋塞米及其注射液的杂质谱,同时检测和分析来源于国内外多家企业的产品,评价该产品的杂质控制现状,以及注射液的主要降解杂质与处方、包装材料的相关性。方法:采用YMC Hydrosphere C_(18)(250 mm×4.6 mm,3μm)色谱柱,以0.05%三氟乙酸溶液(pH 2.23)-甲醇-乙腈为流动相,梯度洗脱,流速1.0 mL·min^(-1),检测波长238 nm和277 nm,柱温30℃。计算各杂质与呋塞米的相对保留时间(RRT),已知杂质采用加校正因子(f)的主成分自身对照法计算,未知杂质为不加校正因子的主成分自身对照法。结果:建立了呋塞米及其注射液中11个已知杂质和1个潜在基因毒杂质的检测方法,各杂质分离度均符合要求,通过强制降解试验归属了各杂质来源。2~3家企业注射液中降解杂质C和降解杂质G的检出量比ICH的鉴定限度大0.2%,5家企业注射液中潜在基因毒杂质糠醛的检出量远高于参比制剂。结论:建立的HPLC方法可用于呋塞米及其注射液中杂质的快速检测分析,国内只有2家企业生产的注射液杂质控制水平基本与参比制剂一致,其他企业需优化处方和包装材料,本研究可为提高呋塞米注射液的安全性和仿制药质量一致性评价研究提供参考。

LMP1 activates NF-κB via degradation of IκBα in nasopharyngeal carcinoma cells

Abstract:Objective To elucidate the mechanisms by which Epstein-Barr virus-encoded latent membrane protein 1 activates NF-κB in nasopharyngeal carcinoma cells.Methods A tetracycline-regulated LMP1-expressing nasopharyngeal carcinoma cell line, Tet-on-LMP1-HNE2, was used as the cell model. The kinetics of the expression of proteins, including LMP1, IκBα and IκBβ, was analyzed by Western blotting. The subcellular localization of NF-κB (p65) was detected by indirect immunofluorescence assay. The NF-κB transactivity was studied by transient transfection and reporter gene assay. Results IκBα was phosphorylated and degraded after the inducible expression of LMP1, although the total protein levels remained stable. The steady-state level of total IκBβ protein may have resulted from the initiation of an autoregulation loop after the activation of NF-κB. No change in the IκBβ level was detected. NF-κB (p65) was translocated from the cytoplasm to the nucleus following degradation of IκBα. After the introduction of the dominant-negative mutant of IκBα (Del 71) into Tet-on-LMP1-HNE2 cells, both nuclear translocation and transactivation of NF-κB induced by LMP1 was significantly inhibited. Conclusions The results indicated that in nasopharyngeal carcinoma cells, LMP1 activated NF-κB via phosphorylation and degradation of IκBα, but not IκBβ. The dominant-negative mutant of IκBα (Del 71) could completely inhibit both the nuclear translocation and transactivation of NF-κB induced by LMP1.

Comparison between chikungunya and dengue viruses transmission based on a mathematical model

Chikungunya and dengue viruses are transmitted by mosquitoes of genus Aedes. Based on a mathematical model dealing with arboviruses transmission that encompasses human and mosquito populations, the risks of dengue and chikungunya infections are compared. By the fact that chikungunya virus attains high viral load earlier than dengue virus in both humans and mosquitoes, the potential risk of chikungunya could be higher than the dengue infection. The risk of arboviruses infections is assessed by the reproduction number R, which is obtained by the next generation matrix method and Routh-Hurwitz criteria.

Kaposi's sarcoma-associated herpesvirus:Towards better understanding of its latency and pathogenesis

Kaposi's sarcoma-associated herpesvirus(KSHV) is a double stranded DNA virus.It was found to be related to Kaposi's sarcoma(KS),primary effusion lymphoma(PEL) and multicentric Castleman's disease(MCD),which cause severe illness in AIDS patients.As a member of human herpesvirus family,KSHV displays two distinct phases in its life cycle,the default latent and lytic replication phase.Following primary infection,the virus can quickly establish latent infection in the host.However,it is still not fully understood up to date how KSHV establishes and maintains viral latency in the host cells.KSHV mainly infects endothelial cells in the host,promoting proliferation and angiogenesis.Abundant angiogenesis is the key feature of KS and is the critical factor for KS progression.The mechanism of KSHV mediated pathogenesis is also largely unknown.In this review,we summarize the recent progress in the mechanisms of KSHV latency and pathogenesis,with particular views from our work.